The man investigators say randomly stabbed and killed three people in Manhattan last month has pleaded not guilty to murder charges, prosecutors say.

Ramon Rivera, 51, was indicted Thursday on one count of first-degree murder, three counts of second-degree murder and one count of third-degree burglary, the Manhattan district attorney’s office said.

In a statement, Manhattan District Attorney Alvin Bragg called the attacks “unprovoked and violent.”

“These fatal stabbings have shaken our city, and those who commit random acts of violence will face accountability,” Bragg said. “My heart goes out to the loved ones of those who were tragically and senselessly killed: Angel Lata Landi, Chang Wang, and Wilna Augustin.”

The stabbing spree began on the morning of Nov. 18 in Chelsea, where authorities say Rivera fatally stabbed Lata Landi, a 35-year-old construction worker, at his job site.

Prosecutors say Rivera went on to kill 67-year-old Wang, who was fishing along the East River at the time, and 36-year-old Augustin, who was sitting on a park bench in Midtown East.

Rivera was arrested in Midtown East soon after the third attack, according to prosecutors.

Prosecutors also say Rivera broke into a hardware store in Gramercy Park hours before the first attack and stole a small backpack, kitchen knives and construction gloves.

Police said Rivera had been arrested eight other times on charges including robbery, grand larceny, burglary, assault and petit larceny.

Authorities said he has a history of mental health issues.

Rivera, who will continue to be held without bail, is due back in court on Jan. 16, the DA’s office said.